ProSoft Technology MVI69-PDPMV1 - Manual (Page 90)

Mailbox Messaging MVI69-PDPMV1 ♦ CompactLogix or MicroLogix Platform
User Manual PROFIBUS DPV1 Master
Page 90 of 225 ProSoft Technology, Inc.
July 8, 2011
4.4.2 Mailbox Message: Set Slave Mode
In addition to station-related user data transfer, which is executed automatically,
the Master can send control commands to a single slave, a group of slaves, or all
slaves simultaneously. These control commands are transmitted as multicast
commands. This permits use of sync and freeze modes for event-controlled
synchronization of the slaves.
The slaves begin sync mode when they receive a sync command from their
assigned Master. The outputs of all addressed slaves are then frozen in their
current state. During subsequent user data transmissions, the output data are
stored on the slaves, but the output states remain unchanged. The stored output
data are not sent to the outputs until the next sync command is received. Sync
mode is concluded with the unsync command.
Similarly, a freeze control command causes the addressed slaves to assume
freeze mode. In this operating mode, the states of the inputs are frozen until the
Master sends the next freeze command. Freeze mode is concluded with the
unfreeze command.
Note 1: It is only possible to send control commands when operating mode is either "CLEAR" or
"OPERATE".
Note 2: Not all slaves support this feature. Refer to the documentation for the actual slave for more
information.
Parameter Description
Command Initiator Application
Command Name SET SLAVE MODE
Command Number 0300h
Fragmented No
Extended Header Data Fault information may be returned in the header of the response.